1. Field of the Invention
The present invention relates to a cable broadcast receiving apparatus and a composing method of a channel map thereof. More particularly, the present invention relates to a cable broadcast receiving apparatus in which a channel map is composed by using a Point-of-Deployment (POD) cable card in an open cable broadcast system, and a composing method of a channel map thereof.
2. Description of the Related Art
In general, a cable broadcast receiving apparatus in an open cable broadcasting system is divided into a host and a POD module. The host refers to a set-top box that receives and processes a cable broadcast signal, or a Digital Cable Ready (DCR) TV that features a combined set-top box and TV. The POD module refers to a processing module that receives encoded contents from a head-end and decodes it. The POD module which is manufactured in a type of Personal Computer Memory Card International Association (PCMCIA) card is connected to a set-top box or a DCR TV for use.
Conventional open cable broadcast systems have two types of channels. One is the in-band (INB) channel for receiving audio/video programs that a viewer can watch, and the other is the out-of-band (OOB) channel in which it is possible to communicate bi-directionally between a broadcasting station and a cable broadcast receiving apparatus, such as a digital set-top box or a DCR TV, and independently in a manner that is transparent to the user.
The OOB channel requires a POD module for processing. The POD module receives the OOB system information (“SI”) data through the OOB channel, and transmits data tables included in the OOB SI data to the host after processing the tables to be compatible with the POD module.
In a conventional open cable broadcast receiving apparatus having such a POD module, the use of the OOB SI data is common for composing a channel map. The POD module processes channel map information through the OOB SI data. However, if incorrect channel information is offered in the POD module, the POD module may fail to detect the channel signal due to the incorrect channel information when tuning to a desired channel. Thus, a user's inability to watch a desired broadcast channel, is recognized as being a problem of the host.